Metallic coatings ranging in thickness from less than a nanometer up to several microns have been added to sheet materials to provide a decorative appearance and/or various physical characteristics such as, for example, electrical conductivity, static charge resistance, chemical resistance, thermal reflectivity or emissivity, and optical reflectivity. In some situations, metallized sheet materials can be applied to or incorporated in some or all portions of a product instead of metallizing the product itself. This may be especially desirable for products that are, for example, large, temperature sensitive, vacuum sensitive, difficult to handle in a metallizing process, or have complex topographies.
In the past, such use of metallized sheet materials may have been restricted by the limitations of the substrate sheet. In the past, metallic coatings have typically been applied to sheet-like substrates that are considered to be relatively stretch-resistant and inelastic so that the substrate would not deform and cause the metallic coating to detach or flake off. Accordingly, such metallized materials may possess inadequate flexibility, stretch and recovery, softness and/or drape properties for many applications. For example, U.S. Pat. Nos. 4,999,222 and 5,057,351 describe metallized polyethylene plexifilamentary film-fibril sheets that are inelastic and have relatively poor drape and softness which may make them unsuited for applications where stretch and recovery, drape and softness are required. European Patent Publication 392,082-A2 describes a method of manufacturing a metallic porous sheet suitable for use as an electrode plate of a battery. According to that publication, metal may be deposited on a porous sheet (foam sheet, nonwoven web, mesh fabric or combinations of the same) utilizing processes such as vacuum evaporation, electrolytic plating and electroless plating.
Thus, a need exists for a stretchable metallized sheet material which has desirable flexibility, stretch and recovery, drape, and softness. There is a further need for a stretchable metallized sheet material which has the desired properties described above and which is so inexpensive that it can be discarded after only a single use. Although metallic coatings have been added to inexpensive sheet materials, such inexpensive metallized sheet materials have generally had limited application because of the poor flexibility, stretch and recovery, drape and softness of the original sheet material.